Hot-blast stove



A. BOWLAND HoT-LAsT STOVE Oc t. s, 1945;

2 Sheet's-'Sheet 1 Filed Aug. 3, 1942 INVENTOR: fl/VDEEW OWL/VD,

HS ATTORNE Oct. 8, 1946. A. BOWLAND HOT-BLAST STOVE 'Filed Aug. 3, 1942 2 Sheets-Shet 2 INVENTOR I Jy/ ylem Baz mmm,

Patented Oct. 8, 1946 &408328 '-HOT-'BLAST ApplicationAugust 3, 1942, -SeriaLNo;4532353 'This invention -relates to hotblast-stoves, 'of i ;the type used toheatthe blast of an ironblast- -furnace, the object beingto ,provide the syn- `thetic rubber industry with a stove of this 'type ?capable of Operating at the high; temperatures .required by this industry,-which are considerably higher than ;the `safe ,Operating limits of prior .art blast-furnace hot-blast stoves. :Ingaddition to its special field, a stove embodying the ;inven- .tioncan be used whereveritstype is required. A specific exampleof -a hot-blast stove con- -structed-according to ?the ;principles of this' inventiomis 'illustrated by the accompanyng ,drawings, the various figures being as follows: Figure-lgisa vertical section'ofthe stove;

Figure z isa horizontal cross-section ;from the .line II-IIin Big-,ure 1pn-an-en1arged scale; and -Figure :3 is ;ai vertical :cross-.section from the line III-'III in l'igure 1 on a,.sti1l:further=en- -larged scale;

-More specifically, :these drawings show. a 'vertical substantially cylindrical steelshell I supporting a steel dome--Z onits top, this dome ,12 %having v a cylindrical.stee1;side :3 from whichrtwo vertically elongated laterally'spaced steelducts 4'extend substantiallyv horizontally :With: their `en'ds converging andconnecting fwith .the cylindrical ;side-5 -of ;asmaller` secondsteel .dome 6 sothat 't s second deme is i supported :by the :first "dome :2 :which is, in turn, 'supportedbythestel shell I, theatter, of course, restingson-the ground. :The 'duct 4 'function vertically.,as cantilevers carrying the weight of the dome 6, and function'laterally as struts.providing ilateral rigidity. i The ducts 4 provide greater rigidity as cantilevers by reason of being made .with Vertically elongated crosssections. This second dome 6 connects through a thermal expansion connection "I with a second Vertical substantially cylindrical steel shell 8 having it own supporting means in the form of a platform 9 on which its bottom rests.

The above Construction involves the advantage that thermal expansion vertically is balanced throughout the structure, the two domes 2 and 6 mOVng V t y as a unit when the shell I moves vertically, the shell 8 being unaffected by this movement since it is working through the expansion connection 1, this also meaning that the shell 8 is free to move vertically independently of the shell l and the two domes.

Inside the shell I is the stove's vertical brick checkerwork o with its laterally enclosing vertical brick lining I I, all this brickwork being carried by the stove bottom z independently of the shell l and being relieved of the weight of the i 3 Clams. 01163419) domes- 2-and =s- -by this' shell 'I "I'hermal 'eXpanision spaceis-providd;between the outsideof the ;lining 'I Land the inside' of the shell-1 ,fiandithere is room;*insidetheidome *2' for 'all the brickwork to thrmally expand without moving this deme. Boththesteel domes =2:,and 6 support'brick :linings 13 andi 1 .4;: respectively, these linings: Testing on -inwardly extending flanges of the' cylindrical dome sids r 3 `and 5,; respec'tively, and thermal -expan- :sion' spaces :being provided between the out'sides of the brick lining .and :the 'insides 'of :the two steel sdomes. The --interconnecting ;steel 'du'cts 4 rare'vprovided 'with tflat-bottonis, :straight *vertical sides :and rarched roofs; this* permittingthem ::to

'be lined 'with ?standard "size'd ,bricks "formin'g 'arched- -topped: ducts r 1:5 which i constitute :brick linings ifor :the stee'l ducts '4, these, brick linin'gs or du ct l b'eing' "bufltintoiihe linngs l 3 and `1 4 so they are also supported by the domei side fi'anges, *and :having expansion "spaces between their'outsides andi-,he insides of the 'steeiducts'at their hottoms, :sides and tops.

"The-;second 'steel domere andits brick lining !4 *are much smaller 'than 'thetzste'etdome'fiz and -its jbrick'ilinirg 13, "the second `steel :shell -8 being likewiseaconsiderably smaller than :the steel shell l 'and containinga brick. lining 16 the weight of which-is carrie d'byrthe support 9 and which has -its :outside 'spaced from'the inside of the steel 'shellssa toprovide atherm'arexpansion space. .The brick ilining 1 6 -of this second cylindere 'is provided with a burnerconnection '-`|`1 and corstitutes the stove's combustion chamber.^'Thus, ;the st'ove is of'the externai combustion chamber type,athe cdmbustionchamber bei'ng entirely out'- side of .the checkerwork n and the lining i l, and

V laterally spaced therefrom as an independent unit. i v v In operation, a burner is connected at the connection !1, and combustion o ccurs inside the lining !6 in the manner necessary to produce the high temperatures required by the'synthetic rubber industry. This introduces no complications because the vertical combustion chamber brick' lining !E can thermally expand without affecting any of the other stove parts, this likewise being true of the combustion chamber steel shell 8. This isimportant because these 'are the hottest parts of the stove. The top of the Vertical brick lining !6 telescopes inside the bottom of the brick lining !4 of the deme side 5, to an extent sufllcient for safety purposes, there being no `conneci tion between the two, however.

The combustion products exhaust into the brick ining I 4 of the steel dome E and travel from there v into the checkerwork dome so as to avoid local damage, particularly, to the top of the checkerwork. To enhance this protection, the top of the checkerwork is positioned well below the level of the ducts, this, in conjunction with the vertical cylindrical sides of the checkerwork dome, providing a large expansion space for the combustion products. The combustion products then travel evenly down through the checkerwork m and out through the bottom of the stove.

During the necessary cyclic operation, the teme perature of the checkerwork varies between extremes, but this does not upset the balanced construction of the stove. Thus, the checkerwork ID and the brick lin'ng H may thermally expand without affecting the steel shell I, and the latter can likewise thermally expand, it carrying both the domes 2 and 5 which can move independently of the steel combustion chamber steel shell 8, by l reason of the thermal expansion connection 1. This independence is important because of the temperature differentials, such as those existing between the combustion chamber and checkerwork, for instance. As in the case of the lining |6 in the combustion chamber, the lining l l eX- tends upwardly into safe telescoping relationship inside the depending lining of the checkerwork dome, the two parts being entirely free for relative movement. In no instance is any of the brickwork required to support anything other than its own weight, and there is no instance where the thermal expansion of the brickwork is restrained in any manner.

It is because of these constructional details which permit the stove to operate as a balanced Construction with all of its parts free to thermally expand to the varying extents resulting from their varying temperatures, that the stove can operate safely at the hightemperatures required by the synthetic rubber industry. Before closing, attention is called to Patent No. 2,257,453 showing a stove shell and thermal insulation particularly adapted for incorporation in the present invention, this not being illustrated by the drawings in the present instance, to avoid confusion with the fundamentals here involved.

I claim:

1. In a hot blast stove comprising an insulating wall having checker tile mounted therein and 4 having a sheet metal housing spaced from the outer wall thereof, a, combustion chamber spaced from said checker tile structure having an insulating Wall and a sheet metal lining spaced from the outer wall thereof, domes mounted on the respective checkerwork and combustion chamber structures having communicating ducts laterally spaced to deliver the products of combustion from the combustion chamber over substantially the entire area above the Checker tile, said ducts being of a greater horizontal cross-sectional area `than the dome above the combustion chamber,

said domes and ducts having a sheet metal outer housing connected to the housing of the combustionchamber by a thermal expansion joint whereby the duct connected domes are vertically movable as a. unit in response to thermal expansion of the checkerwork wall.

2. In a hot blast stove comprising a checkerwork unit and a, combustion unit communicating to deliver the products of combustion to the top of the checkerwork unit, oa plurality of domes mounted on top of said units joined by laterally spaced ducts of greater horizontal cross-sectional area than the dome above the combustion unit,

'said ducts being spaced to distribute the products of combustion substantially uniformly over the entire area of the checkerwork in the chamber formed by the checkerwork unit dome, the combustion unit dome having thermal expansion connection with the wall of the combustion unit and said checkerwork and combustion unit domes and communicating ducts having sheet metal housings 3. In a, hot blast stove a checkerwork unit and a combustion unit having domes forming chambers at the top thereof communicating through a plurality of laterally spaced ducts, the longitudinal cross-sectional area of which is greater than the dome above the combustion unit and being spaced to distribute the products of combustion substantially uniformly over the entire area at the top of the checkerwork, said checkerwork, combustion unit and domes having refractory linings and sheet metal housings interacting to be independently movable responsive to therma1 expansion, the dome and duct structures constituting a monolithic wall with the duct walls functioning vertically as cantilevers carrying the weight of the combustion unit dome to adapt the dome units for thermal movement independently of the checkerwork and combustion unit walls and housings. i

ANDREW BOWLAND. 

